Safety device for elevator driving means



July-ll, 1933. H RQQHE 1,91%462 SAFETY DEvIcE FOR ELEVATOR DRIVING MEANS Filed Dec. 17, 1928 2 Sheets-Sheet l 7' l l W ,wvew 70 a July 11, 1933. H ROCHE 1,917,462

SAFETY DEVICE FOR ELEVATOR DRIVING MEANS Filed Dec. 17, 1928 2 Sheets-Sheet 2 Z a o I gpvvaw TOE Patented July 11, 1933 UNITED STATES PATENT OFFICE HENRI ROCHE, OF PARIS, FRANCE, ASSIGNOR TO SOGIETE ETLAIBLISSEMENTS EDOUX- SAMAIN, OF PARIS, FRANCE SAFETY DEVICEv FOR ELEVATOR DRIVING MEANS Application filed December 17, 1928, Serial No. 326,672, and in France December 23, 1927 In automatic electrically driven lifts or elevators and hoists, the possibility of controlling the same, whether the operation of the driving parts has normally started the driven members or not, is a matter of the utmost importance.

For instance, in the case of elevators of the so-called adherence traction type, in which the driving of the cables connecting :the car to the counter-weight is effected by friction upon grooved pulleys of suitable form, it is necessary to prevent the driving pulley from turning without carrying along the cables, car and the counter-weight because, in the case of slippage, the movement of the cables in the grooves of the pulley .eventually render the latter unfit for use.

The present invention has for its object the provision of a safety device which will stop theoperation of the drivinpmeans in the second, means actuated by the driven members and acting as soon as they are driven does not render ineifective the action of the first means which, as will be understood, will be the case so long as the parts of the apparatus regularly and properly function.

For example, the first means may be an electric contact which is closed when the parts of the electric driving mechanism are at rest and which opens after a period of time t (for instance ten seconds) after the starting operation. The second means may then be an electric contact connected in parallel with the first contact and opened when the driven members are at rest and closed as soon as the latter are actuated. In this way it shunts the first contactand renders its open ing inoperative. Both contacts can be inserted in the blocking circuit of the driving mechanisms. This will be called the two parallel contacts device.

On the other hand, the first means may be an electric contact open when the electric driving mechanism is at rest and closing after the time period t after starting. The second means may then be a second contact connected in series with the first contact, closed when the driven members are at rest and opened as soon as they are actuated. In this way, it prevents the closing of the circuit ,of both contacts, the circuit feeding a disconnecting relay which causes the apparatus to stop. The action of the second contact thus renders inoperative the closing of the first contact. This will be called the two-series contacts device.

The accompanying drawings show by way of example, two embodiments of the present invention applied to an electric traction elevator.

In the drawings:

Figure 1 is a diagrammatic View of the first embodiment of the invention and shows the main parts of an electric driving mechanism controlled by push buttons provided with a device having two contacts in parallel.

Fig. 2 is a side view partly in section and on a larger scale of the first named type of contact selected as an example.

Fig. 3 is a similar view of a second contact type.

Fig. 4: is a diagrammatic view for use in connection with the explanation of Fig. 1.

Fig. 1 shows the car of cage 1; the traction or hoisting cables 2 the counter-weight 3 the traction driving pulley 4; the speed reducer drum 5; the electric motor 6; the brake drum 7; the brake magnet 8; the endless cable 9 controlling the regulator 10 of the stopping or safety device; the current supply conductors 11 of a three phase system.

Fig. 1 shows the electric reversing device for the motor whereby the ascending and descending movements of the car are effected and also shows the contacts on the brake.

In connection with the electric driving mechanism there is shown also the fuses 14 of said mechanism, the line of circuit closing means starting at 15; the two contacts C1, C2; the stop buttons 16; the wire 17 extending to the car 1; the door contact 18 in the car 1;

floor and the box 27 in the car 1.

the return wire 19; the door contacts 20 at the floors or landings; and the return wire 21. At 22 the conductor 21, common to the push buttons is branched and connected through a gap in the common line for the push buttons 24, supplies the push buttons 25 at the different floors, the button box 26 at the ground The common conductor 29 of the well known floor relays 28 is also connected at the point 22. The numeral 30 denotes the stopping rockers or floor stopping devices for the floor indicators 31 and 32, the relays M (ascent) and D (descent). As shown especially in Fig. 1 (parallel contacts device), the parallel contacts C1, C2 device is in series with the door contacts.

As above stated, the contact C1 is closed during the period when the parts of the electric driving mechanism are at rest. The same opens or closes, according to circumstances, at the end of the time period t after the said parts of the driving mechanism have been set in motion. It again closes or opens when the said parts come to rest. For instance, in the case of the contacts in parallel (Fig. 1), the contact C1 is opened at the end of the period of time t, by virtue of a spring or a counter-weight or other suitable device and is released by the operation of a member of the driving mechanism, brake, starter or the like. Thus, in Fig. 2, the operation of the brake overcomes the tension of the spring 36, moving the device in a direction indicated at 35. The spring 86, thus compressed, then begins to act and due to the action of the dash-pot 37, the contact C1 is actuated after the time period t.

In the case of parallel contacts, the contact (Fig. 1) C2 must be open when the car is stopped, and closed when the latter is moving. It must open as soon as the car stops. The said contact C2 canbe controlled by a centrifugal device connected to the car, and particularly by the safety regulator cont-relling the holding or safety device (when the latter is of the accelerator type). In Fig. 3, when the weights 38 of the safety regulator move apart by centrifugal forces, the springs 39 and 40 expand and the conducting bar bridges across the contact pieces 41 and 43.

Fig. 4 illustrates diagrammatically the use of the devices C1 and G2 with a push button electric driving mechanism. In Fig. 4 the current supply is indicated at 44; the device C1, G2 at 45, a stop button or contact 46, the door contacts 47, the floor relays 48 with their closing cont-acts 49, the common conductor 50 and the return conductor 51 for the buttons, the rockers or floor stopping devices 52, the relays M (ascent) and D (descent) at 53. The opening of the circuit in which the contacts G1, G2 (Fig. 4) are inserted cuts off every controlled operation.

Thus the different circuits of the installation are as follows:

Fig. 1: The device in parallel C1, C2 is inserted in the circuit of the door contacts between 15 and 16.

Fig. 4: The device in parallel C1, C2 is inserted in the circuit of the door contacts, but between 44 and 46.

The main advantage of the invention con sists in closing the electric driving mechanism of an elevator of the traction type only when the adherence of the cable on the traction pulley is normal.

Further advantages of the invention are as follows:

Prevention of damage to the motors in case they do not start when, for instance with polyphase current, one phase is cut out or when for any reason the resistance couple is accidentally higher than the motive couple. At the end of the period of time t after the electric driving mechanism has been started, the contact C1 opens; if the motor has not started C2 remains open so after the time t the circuit of the contacts C1, C2 is cut out and the electric driving mechanism returns to the position of rest, thereby obviating the possiblity of excessive heating of the motor.

Permanent control for the correct operation of the safety regulator for elevators and hoists. In order to obtain this control, it is only necessary to have the contact C2 controlled by the regulator itself. If, for any reason further movement of the regulator is prevented, thereby depriving the installation of the safety afforded by the centrifugal mechanism of the regulator, the contact C2 would remain open and the driving mechanism would be stopped.

In the same way, in case the cable 9 (Fig. 1) controlling the movement of the regulator should break, the regulator remaining stationary, the contact C2 would remain open and movement of the elevator would be stopped.

\Vhat I claim is 1. In a safety device for electric elevators, an operating mechanism for raising and lowering the elevator, a number of driven members thereon, an electriedriving mechanism for actuating the operating mechanism and the driven members, a first contactmreans, and a controluneans therefor, jointly operable to automatically stop the electric drivingmechanism, and in turn the operating mechanism, at the end of a short period of time, after the same are started, if the driven members are not operating normally, and a second contact-means electrically connected with the first contact-means, controlled by the action of the driven members, and acting to prevent the first contact-means and its control-means from eifecting the stoppage of the electric driving mechanism as long as the driven members normally operate.

2. In a safety device for electric elevators, an operating mechanism for raising and lowering the elevator, a number of driven members thereon, an electric driving mechanism for actuating the operating mechanism and the driven members, a first contact-device connected to the electric driving mechanism electrically closed when the driven members are in stopped position, and automatically opened electrically, at the end of a short period of time, after the electric driving mechanism has been placed in operation, control-means for operating the first contactdevice, a second contact-device in electric circuit with the first contact device and controlled by the action of the operating mechanism and the driven members, placed in electrically open position when the driven members are not in operation, and in electrically closed position during the time the said members are in normal operation.

3. In a safety device for elevators, an operating mechanism for raising and lowering the elevator, electric driving means for actuating said mechanism, a first contactdevice, and a control-means therefor, jointly operable to stop the electric driving means at the end of a short period of time, after the operating mechanism has been placed in operation, a second contact device connected in parallel in an electric circuit with the first contact-device, controlled by the elevator operating mechanism, and acting to prevent the first contact-device and its control-means from effecting the stoppage of the electric driving means and the operating mechanism, as long as the operating mechanism normally operates.

4. In a safety device for electric elevators, an operating mechanism for raising and lowering the elevator, a number of driven members thereon, an electric driving mecha nism for actuating the operating mechanism and the driven members, a first contactmeans, and a control-means therefor, jointly operable to automatically stop the electric driving mechanism, and in turn the operating mechanism at the end of a short period of time, after the same are put into opera.-

7 tion, if the driven members are not operating normally, and a second contact-means arranged in parallel in an electric circuit with the first contact-means, controlled by the action of the driven members, and acting to prevent the first contact-means and its control-means from effecting the stoppage of the electric driving and operating mechanisms, as long as the driven members normally operate, and a door-contacts circuit in the circuit of the electric driving mechanism, and in circuit with the contact-devices.

5. In a safety device for electric elevators, an operating mechanism for raising and lowering the elevator, a plurality of driven members thereon, an electric driving mechanism for actuating the operating mechanism and the driven members, a first contact-device for operating the electric driving mechanism, a dash-pot having members adapted to hold the first contact-device in electrically open position when the driven members operate normally, electro-magnetic means to release the said dash-pot members and effect the electrical closure of the first contact-device when the driven members are at rest, and a second contact-device electrically connected with the first contact-device, controlled by the operation of the driven members, and acting to prevent the first contact-device, the dashpot, and the electro-magnet-ic means from effecting the stoppage of the electric driving mechanism, as long as the driven members normally operate.

6. In a safety device for an electric elevator having a car therein, an operating mechanism for raising and lowering the elevator car, a number of driven members thereon, an electric driving mechanism for actuating the operating mechanism and the driven members, a first contact-device and a controlmeans therefor, jointly operable to automatically stop the electric driving mechanism at the end of a short period of time after the same is put into operation, if the driven members are not operating normally, and a second contact-device electrically connected with the first contact-device, acting to prevent the latter and its control-means from stopping the electric driving mechanism, as long as the driven members are operating normally, and a centrifugally operated control-means, to control the action of the second contact-device, and actuated by the movement of the elevator car.

In testimony whereof I have hereunto afiixed my signature.

HENRI ROCHE. 

